Many of the songs have rock-anthem flourishes, as heard on the title track, as well as softer, folk moments, as evidenced on the album's second single, "Story Of My Life."
While some fans were initially skeptical of the updated sound on the group's third studio release, they now love it.
"It took me a second to like it 'cause I listened to it first and then I was not sure," Joy told MTV News outside of "Good Morning America" where 1D performed and announced 2014 tour dates. "But then I kept listening to it and I got used to it and I started liking it."
Angela added, "To be honest, at first, I was kind of like 'Oh, you know, this isn't the original stuff that they do,' but eventually I really started liking it. I liked how it's getting older."
According to the loyal Directioners, Midnight Memories shows the band's musical and lyrical growth from Up All Night and Take Me Home, which was released just last November.
"Well I think the first two albums kind of had like a bubblegum poppy kind of sound," Rachael said. "And this is more kind of like classic rock sounding. And it's something that they've never done before. But I think they're doing a great job with it and it's cool to hear something different, kind of keeps people interested, keeps us on our toes."
Sasha noted that it's "like indie rock. I love how they've become indie rock; it's amazing."
Other fans think 1D's musical growth mirrors their real-life move into adulthood.
"It just fits their personality and how they're growing up more and more," Taleyah said.